Question

in a mathematics paper there are 10 problems. each correct answer carrie 5 marks whereas for each incorrect answer 2 marks are deducted from the marks scored .aman answered all the questions but got only 29 marks. find the number of correct answers given by aman.

Answer 1

Step-by-step explanation:

No. of total pblms : 10

let the number of correct answers be 'x'

therefore,

correct answer = x

wrong answer = 10-x

for each correct answer,

he gets +5 marks

1 question- 5 marks

x questions- 5x marks

for each wrong answer,

he gets -2 marks

1 question- -2 marks

10-x questions- (-2)(10-x)

= 2x - 20 marks

therefore aman gets

5x marks by his correct answers

2x-20 marks by his wrong answers

total marks = 29

therefore,

5x + 2x - 20 = 29

7x-20=29

7x=49

x=7

hence he answered

correct answer = x = 7 questions

wrong answer = 10-x= 3 questions